Re: [PATCH v2 12/18] mm/gup: track FOLL_PIN pages

2019-11-04 Thread John Hubbard
Hi Dan, there is a question for you further down: On 11/4/19 3:49 PM, Jerome Glisse wrote: > On Mon, Nov 04, 2019 at 02:49:18PM -0800, John Hubbard wrote: ... >>> Maybe add a small comment about wrap around :) >> >> >> I don't *think* the count can wrap around, due to the checks in >> user_page_

Re: [PATCH v2 12/18] mm/gup: track FOLL_PIN pages

2019-11-04 Thread Jerome Glisse
On Mon, Nov 04, 2019 at 02:49:18PM -0800, John Hubbard wrote: > On 11/4/19 10:52 AM, Jerome Glisse wrote: > > On Sun, Nov 03, 2019 at 01:18:07PM -0800, John Hubbard wrote: > >> Add tracking of pages that were pinned via FOLL_PIN. > >> > >> As mentioned in the FOLL_PIN documentation, callers who eff

Re: [PATCH v2 12/18] mm/gup: track FOLL_PIN pages

2019-11-04 Thread John Hubbard
On 11/4/19 10:52 AM, Jerome Glisse wrote: > On Sun, Nov 03, 2019 at 01:18:07PM -0800, John Hubbard wrote: >> Add tracking of pages that were pinned via FOLL_PIN. >> >> As mentioned in the FOLL_PIN documentation, callers who effectively set >> FOLL_PIN are required to ultimately free such pages via

Re: [PATCH v2 12/18] mm/gup: track FOLL_PIN pages

2019-11-04 Thread Jerome Glisse
On Sun, Nov 03, 2019 at 01:18:07PM -0800, John Hubbard wrote: > Add tracking of pages that were pinned via FOLL_PIN. > > As mentioned in the FOLL_PIN documentation, callers who effectively set > FOLL_PIN are required to ultimately free such pages via put_user_page(). > The effect is similar to FOL

[PATCH v2 12/18] mm/gup: track FOLL_PIN pages

2019-11-03 Thread John Hubbard
Add tracking of pages that were pinned via FOLL_PIN. As mentioned in the FOLL_PIN documentation, callers who effectively set FOLL_PIN are required to ultimately free such pages via put_user_page(). The effect is similar to FOLL_GET, and may be thought of as "FOLL_GET for DIO and/or RDMA use". Pag